Advancing a multivalent ‘Pan-anthelmintic’ vaccine against soil-transmitted nematode infections

Zhan, Bin; Beaumier, Coreen M; Briggs, Neima; Jones, Kathryn M; Keegan, Brian P; Bottazzi, Maria Elena; Hotez, Peter J

KEYWORDS: Ascaris lumbricoides . Ascaris suum, deworming . geohelminth . hookworm . intestinal helminth . Necator americanus . Pan-anthelmintic vaccine . soil-transmitted helminth . soil-transmitted nematode . Trichinella spiralis . Trichuris muris . Trichuris trichiura Rationale for a Pan-anthelmintic vaccine The three major soil-transmitted nematode infections, in other words, ascariasis, trichuriasis and hookworm infections, are highly prevalent neglected tropical diseases that rank near the top of the list of most common human afflictions [1] . According to some estimates, approximately 800 million people are infected with the roundworm, Ascaris lumbricoides, and 600 million people with the whipworm, Trichuris trichiura or hookworms, mostly by Necator americanus [1, 2] . There is widespread geographical overlap of these three soiltransmitted nematode infections (also referred to as soil-transmitted helminth, intestinal helminth, intestinal nematode or geohelminth infections) in impoverished areas of sub-Saharan Africa, East Asia and South Asia and tropical regions of Central and South America [3] . Coinfections with two or even all three soil-transmitted nematode infections are extremely common in children [2, 3] . The WHO currently estimates that 874.5 million children are infected or exposed to A. lumbricoides, T. trichiura and hookworms, and therefore, require regular and periodic anthelmintic treatment ('deworming') (TABLE 1) [4] . Such children are often chronically infected and suffer from long-term disabling consequences including growth stunting, reductions in physical fitness, and cognitive and intellectual delays [2] . Moreover, there are millions of pregnant women in developing countries with soiltransmitted nematode infections, especially hookworm infection [5] . Recent estimates from the Global Burden of Disease Study 2010 indicate that soil-transmitted nematode infections are responsible for 5.18 million disabilityadjusted life years, which leads all neglected tropical diseases [6] . In addition, ascariasis is responsible for 2,700 deaths annually [7] .